Objective To investigate the influences of different indwelling time of venous indwelling needle on inflammatory factors, oxidative stress indexes and coagulation factors in the ear vein of white rabbits.

Methods Forty New Zealand white rabbits were randomly divided into control group, 4-day indwelling group, 6-day indwelling group and 8-day indwelling group, with 10 rabbits in each group. In the indwelling groups, the ear vein of the rabbit was punctured with intravenous indwelling needles. Blood and ear vein samples were collected on the 4th, 6th and 8th days after indwelling, and blood routine tests were performed. Enzyme Linked Immunosorbent Assay (ELISA) was used to detect the levels of interleukin (IL)-1, IL-6 and tumor necrosis factor alpha (TNF-α) in ear vein vascular tissue and levels of serum thromboxane B2 (TXB2), 6-keto-prostaglandin F1a (6-keto-PGF1a) and endothelin 1 (ET-1). Biochemical methods was used to measure the levels of malondialdehyde (MDA), the activities of superoxide dismutase (SOD) and glutathione peroxidase (GSH-Px) in ear vein vascular tissue. Hematoxylin and eosin (HE) staining was used to observe the histopathological changes of rabbit ear veins.

Results Compared with the the other three group, the levels of white blood cells (WBC), platelet (PLT), neutrophilic granulocyte percentage (Gran), IL-1, IL-6, TNF-α, MDA, TXB2, ET-1, the degree of vascular inflammation and the incidence of thrombosis were significantly increased in the 8-day indwelling group, while the activity of SOD, GSH-Px and the level of 6-keto-PGF1a were significantly decreased(P < 0.05).

Conclusion Indwelling time of indwelling needles for more than 6 days will increase inflammatory factors in ear veins, induce oxidative stress, and aggravate phlebitis and thrombosis.